asn1/ber/src/main/java/org/apache/directory/api/asn1/ber/tlv/TLV.java - directory-ldap-api - Git at Google

 /*
  *  Licensed to the Apache Software Foundation (ASF) under one
  *  or more contributor license agreements.  See the NOTICE file
  *  distributed with this work for additional information
  *  regarding copyright ownership.  The ASF licenses this file
  *  to you under the Apache License, Version 2.0 (the
  *  "License"); you may not use this file except in compliance
  *  with the License.  You may obtain a copy of the License at
  *
  *    https://www.apache.org/licenses/LICENSE-2.0
  *
  *  Unless required by applicable law or agreed to in writing,
  *  software distributed under the License is distributed on an
  *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  *  KIND, either express or implied.  See the License for the
  *  specific language governing permissions and limitations
  *  under the License.
  *
  */
 package org.apache.directory.api.asn1.ber.tlv;


 import org.apache.directory.api.asn1.util.Asn1StringUtils;


 /**
  * This class is used to store Tags, Lengths and Values decoded from a PDU.
  *
  * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
  */
 public class TLV
 {
     /** The current Tag being processed */
     private byte tag;

     /** The current Length being processed */
     private int length;

     /** The number of byte to store the Length being processed */
     private int lengthNbBytes;

     /** The number of length's bytes currently read */
     private int lengthBytesRead;

     /** The current Value being processed */
     private BerValue value;

     /** An identity for the TLV. It store the TLV hashCode */
     private int id;

     /**
      * Reference the TLV which contains the current TLV, if any. As the
      * enclosing TLV of a PDU does not have parent, it can be null in this case.
      * Otherwise, it must point to a constructed TLV
      */
     private TLV parent;

     /**
      * The expected length of the TLV's elements, if the current TLV is a
      * constructed TLV.
      */
     private int expectedLength;

     /** tag flag for the primitive/constructed bit - 0010 0000 - 0x20 */
     public static final byte CONSTRUCTED_FLAG = 0x20;

     /** mask to get the type class value */
     public static final byte TYPE_CLASS_MASK = ( byte ) 0xC0;

     /** value for the universal type class */
     public static final byte TYPE_CLASS_UNIVERSAL = 0x00;

     /** tag mask for the short tag format - 0001 1111 - 0x1F */
     public static final int SHORT_MASK = 0x1F;

     /** A mask to get the Length form */
     public static final int LENGTH_LONG_FORM = 0x0080;

     /** Value of the reserved extension */
     public static final int LENGTH_EXTENSION_RESERVED = 0x7F;

     /** A mask to get the long form value */
     public static final int LENGTH_SHORT_MASK = 0x007F;

     /** A speedup for single bytes length */
     private static final byte[][] ONE_BYTE = new byte[128][];

     // Initialize an array of byte[] used for encoding lengths below 128
     static
     {
         for ( int i = 0; i < 128; i++ )
         {
             ONE_BYTE[i] = new byte[1];
             ONE_BYTE[i][0] = ( byte ) i;
         }
     }


     /**
      * Creates a new TLV object.
      *
      * @param id the TLV's id
      */
     public TLV( int id )
     {
         tag = 0;
         length = 0;
         lengthNbBytes = 0;
         value = new BerValue();
         this.id = id;

         expectedLength = 0;
     }


     /**
      * Checks to see if the tag is constructed.
      *
      * @param tag the TLV's tag
      * @return true if constructed, false if primitive
      */
     public static boolean isConstructed( byte tag )
     {
         return ( tag & CONSTRUCTED_FLAG ) != 0;
     }


     /**
      * Checks to see if the current tlv's tag is constructed.
      *
      * @return true if constructed, false if primitive
      */
     public boolean isConstructed()
     {
         return ( tag & CONSTRUCTED_FLAG ) != 0;
     }


     /**
      * Checks to see if the tag represented by this Tag is primitive or
      * constructed.
      *
      * @param tag the tag to be checked
      * @return true if it is primitive, false if it is constructed
      */
     public static boolean isPrimitive( byte tag )
     {
         return ( tag & CONSTRUCTED_FLAG ) == 0;
     }


     /**
      * Tells if the tag is Universal or not
      *
      * @param tag the tag to be checked
      * @return true if it is primitive, false if it is constructed
      */
     public static boolean isUniversal( byte tag )
     {
         return ( tag & TYPE_CLASS_MASK ) == TYPE_CLASS_UNIVERSAL;
     }


     /**
      * Reset the TLV, so it can be reused for the next PDU decoding.
      */
     public void reset()
     {
         tag = 0;
         length = 0;
         lengthNbBytes = 0;
         value.reset();

         expectedLength = 0;
     }


     /**
      * @return Returns the tag.
      */
     public byte getTag()
     {
         return tag;
     }


     /**
      * Set a tag value for this TLV.
      *
      * @param tag the tag field for this TLV.
      */
     public void setTag( byte tag )
     {
         this.tag = tag;
     }


     /**
      * @return Returns the value.
      */
     public BerValue getValue()
     {
         return value;
     }


     /**
      * The TLV size is calculated by adding the Tag's size, the Length's size
      * and the Value's length, if any.
      *
      * @return Returns the size of the TLV.
      */
     public int getSize()
     {
         return 1 + lengthNbBytes + length;
     }


     /**
      * Utility function that return the number of bytes necessary to store the
      * length
      *
      * @param length The length to store in a byte array
      * @return The number of bytes necessary to store the length.
      * @see <a href="http://en.wikipedia.org/wiki/X.690#Length_Octets">X.690</a>
      */
     public static int getNbBytes( int length )
     {
         if ( length >= 0 )
         {
             if ( length < 128 )
             {
                 return 1;
             }
             else if ( length < 256 )
             {
                 return 2;
             }
             else if ( length < 65536 )
             {
                 return 3;
             }
             else if ( length < 16777216 )
             {
                 return 4;
             }
             else
             {
                 return 5;
             }
         }
         else
         {
             return 5;
         }
     }


     /**
      * Utility function that return a byte array representing the length
      *
      * @param length The length to store in a byte array
      * @return The byte array representing the length.
      */
     public static byte[] getBytes( int length )
     {
         if ( length >= 0 )
         {
             if ( length < 128 )
             {
                 return ONE_BYTE[length];
             }
             else
             {
                 byte[] bytes = new byte[getNbBytes( length )];

                 if ( length < 256 )
                 {
                     bytes[0] = ( byte ) 0x81;
                     bytes[1] = ( byte ) length;
                 }
                 else if ( length < 65536 )
                 {
                     bytes[0] = ( byte ) 0x82;
                     bytes[1] = ( byte ) ( length >> 8 );
                     bytes[2] = ( byte ) ( length & 0x00FF );
                 }
                 else if ( length < 16777216 )
                 {
                     bytes[0] = ( byte ) 0x83;
                     bytes[1] = ( byte ) ( length >> 16 );
                     bytes[2] = ( byte ) ( ( length >> 8 ) & 0x00FF );
                     bytes[3] = ( byte ) ( length & 0x00FF );
                 }
                 else
                 {
                     bytes[0] = ( byte ) 0x84;
                     bytes[1] = ( byte ) ( length >> 24 );
                     bytes[2] = ( byte ) ( ( length >> 16 ) & 0x00FF );
                     bytes[3] = ( byte ) ( ( length >> 8 ) & 0x00FF );
                     bytes[4] = ( byte ) ( length & 0x00FF );
                 }

                 return bytes;
             }
         }
         else
         {
             byte[] bytes = new byte[getNbBytes( length )];

             bytes[0] = ( byte ) 0x84;
             bytes[1] = ( byte ) ( length >> 24 );
             bytes[2] = ( byte ) ( ( length >> 16 ) & 0x00FF );
             bytes[3] = ( byte ) ( ( length >> 8 ) & 0x00FF );
             bytes[4] = ( byte ) ( length & 0x00FF );

             return bytes;
         }
     }


     /**
      * @return The parent.
      */
     public TLV getParent()
     {
         return parent;
     }


     /**
      * @param parent The parent to set.
      */
     public void setParent( TLV parent )
     {
         this.parent = parent;
     }


     /**
      * Get the TLV expected length.
      *
      * @return The expectedLength.
      */
     public int getExpectedLength()
     {
         return expectedLength;
     }


     /**
      * Set the new expected length of the current TLV.
      *
      * @param expectedLength The expectedLength to set.
      */
     public void setExpectedLength( int expectedLength )
     {
         this.expectedLength = expectedLength;
     }


     /**
      * @return The number of bytes necessary to store the TLV's length
      */
     public int getLengthNbBytes()
     {
         return lengthNbBytes;
     }


     /**
      * Set the number of bytes we should use to store the TLV's length.
      *
      * @param lengthNbBytes The number of bytes necessary to store the TLV's length
      */
     public void setLengthNbBytes( int lengthNbBytes )
     {
         this.lengthNbBytes = lengthNbBytes;
     }


     /**
      * @return the TLV's length
      */
     public int getLength()
     {
         return length;
     }


     /**
      * Set the TLV's length
      *
      * @param length the TLV's length
      */
     public void setLength( int length )
     {
         this.length = length;
     }


     /**
      * @return The currently read TLV's length bytes
      */
     public int getLengthBytesRead()
     {
         return lengthBytesRead;
     }


     /**
      * Set the currently read TLV's length bytes.
      *
      * @param lengthBytesRead the currently read TLV's length bytes
      */
     public void setLengthBytesRead( int lengthBytesRead )
     {
         this.lengthBytesRead = lengthBytesRead;
     }


     /**
      * Increment the number of bytes read for this TLV
      *
      */
     public void incLengthBytesRead()
     {
         lengthBytesRead++;
     }


     /**
      * @return The TLV's ID
      */
     public int getId()
     {
         return id;
     }


     /**
      * Get a String representation of the TLV
      *
      * @return A String
      */
     @Override
     public String toString()
     {

         StringBuilder sb = new StringBuilder();

         sb.append( "TLV[ " );
         sb.append( Asn1StringUtils.dumpByte( tag ) ).append( ", " );
         sb.append( length ).append( ", " );
         sb.append( value.toString() );
         sb.append( "]" );

         return sb.toString();
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* https://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*
	*/
	package org.apache.directory.api.asn1.ber.tlv;


	import org.apache.directory.api.asn1.util.Asn1StringUtils;


	/**
	* This class is used to store Tags, Lengths and Values decoded from a PDU.
	*
	* @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
	*/
	public class TLV
	{
	/** The current Tag being processed */
	private byte tag;

	/** The current Length being processed */
	private int length;

	/** The number of byte to store the Length being processed */
	private int lengthNbBytes;

	/** The number of length's bytes currently read */
	private int lengthBytesRead;

	/** The current Value being processed */
	private BerValue value;

	/** An identity for the TLV. It store the TLV hashCode */
	private int id;

	/**
	* Reference the TLV which contains the current TLV, if any. As the
	* enclosing TLV of a PDU does not have parent, it can be null in this case.
	* Otherwise, it must point to a constructed TLV
	*/
	private TLV parent;

	/**
	* The expected length of the TLV's elements, if the current TLV is a
	* constructed TLV.
	*/
	private int expectedLength;

	/** tag flag for the primitive/constructed bit - 0010 0000 - 0x20 */
	public static final byte CONSTRUCTED_FLAG = 0x20;

	/** mask to get the type class value */
	public static final byte TYPE_CLASS_MASK = ( byte ) 0xC0;

	/** value for the universal type class */
	public static final byte TYPE_CLASS_UNIVERSAL = 0x00;

	/** tag mask for the short tag format - 0001 1111 - 0x1F */
	public static final int SHORT_MASK = 0x1F;

	/** A mask to get the Length form */
	public static final int LENGTH_LONG_FORM = 0x0080;

	/** Value of the reserved extension */
	public static final int LENGTH_EXTENSION_RESERVED = 0x7F;

	/** A mask to get the long form value */
	public static final int LENGTH_SHORT_MASK = 0x007F;

	/** A speedup for single bytes length */
	private static final byte[][] ONE_BYTE = new byte[128][];

	// Initialize an array of byte[] used for encoding lengths below 128
	static
	{
	for ( int i = 0; i < 128; i++ )
	{
	ONE_BYTE[i] = new byte[1];
	ONE_BYTE[i][0] = ( byte ) i;
	}
	}


	/**
	* Creates a new TLV object.
	*
	* @param id the TLV's id
	*/
	public TLV( int id )
	{
	tag = 0;
	length = 0;
	lengthNbBytes = 0;
	value = new BerValue();
	this.id = id;

	expectedLength = 0;
	}


	/**
	* Checks to see if the tag is constructed.
	*
	* @param tag the TLV's tag
	* @return true if constructed, false if primitive
	*/
	public static boolean isConstructed( byte tag )
	{
	return ( tag & CONSTRUCTED_FLAG ) != 0;
	}


	/**
	* Checks to see if the current tlv's tag is constructed.
	*
	* @return true if constructed, false if primitive
	*/
	public boolean isConstructed()
	{
	return ( tag & CONSTRUCTED_FLAG ) != 0;
	}


	/**
	* Checks to see if the tag represented by this Tag is primitive or
	* constructed.
	*
	* @param tag the tag to be checked
	* @return true if it is primitive, false if it is constructed
	*/
	public static boolean isPrimitive( byte tag )
	{
	return ( tag & CONSTRUCTED_FLAG ) == 0;
	}


	/**
	* Tells if the tag is Universal or not
	*
	* @param tag the tag to be checked
	* @return true if it is primitive, false if it is constructed
	*/
	public static boolean isUniversal( byte tag )
	{
	return ( tag & TYPE_CLASS_MASK ) == TYPE_CLASS_UNIVERSAL;
	}


	/**
	* Reset the TLV, so it can be reused for the next PDU decoding.
	*/
	public void reset()
	{
	tag = 0;
	length = 0;
	lengthNbBytes = 0;
	value.reset();

	expectedLength = 0;
	}


	/**
	* @return Returns the tag.
	*/
	public byte getTag()
	{
	return tag;
	}


	/**
	* Set a tag value for this TLV.
	*
	* @param tag the tag field for this TLV.
	*/
	public void setTag( byte tag )
	{
	this.tag = tag;
	}


	/**
	* @return Returns the value.
	*/
	public BerValue getValue()
	{
	return value;
	}


	/**
	* The TLV size is calculated by adding the Tag's size, the Length's size
	* and the Value's length, if any.
	*
	* @return Returns the size of the TLV.
	*/
	public int getSize()
	{
	return 1 + lengthNbBytes + length;
	}


	/**
	* Utility function that return the number of bytes necessary to store the
	* length
	*
	* @param length The length to store in a byte array
	* @return The number of bytes necessary to store the length.
	* @see <a href="http://en.wikipedia.org/wiki/X.690#Length_Octets">X.690</a>
	*/
	public static int getNbBytes( int length )
	{
	if ( length >= 0 )
	{
	if ( length < 128 )
	{
	return 1;
	}
	else if ( length < 256 )
	{
	return 2;
	}
	else if ( length < 65536 )
	{
	return 3;
	}
	else if ( length < 16777216 )
	{
	return 4;
	}
	else
	{
	return 5;
	}
	}
	else
	{
	return 5;
	}
	}


	/**
	* Utility function that return a byte array representing the length
	*
	* @param length The length to store in a byte array
	* @return The byte array representing the length.
	*/
	public static byte[] getBytes( int length )
	{
	if ( length >= 0 )
	{
	if ( length < 128 )
	{
	return ONE_BYTE[length];
	}
	else
	{
	byte[] bytes = new byte[getNbBytes( length )];

	if ( length < 256 )
	{
	bytes[0] = ( byte ) 0x81;
	bytes[1] = ( byte ) length;
	}
	else if ( length < 65536 )
	{
	bytes[0] = ( byte ) 0x82;
	bytes[1] = ( byte ) ( length >> 8 );
	bytes[2] = ( byte ) ( length & 0x00FF );
	}
	else if ( length < 16777216 )
	{
	bytes[0] = ( byte ) 0x83;
	bytes[1] = ( byte ) ( length >> 16 );
	bytes[2] = ( byte ) ( ( length >> 8 ) & 0x00FF );
	bytes[3] = ( byte ) ( length & 0x00FF );
	}
	else
	{
	bytes[0] = ( byte ) 0x84;
	bytes[1] = ( byte ) ( length >> 24 );
	bytes[2] = ( byte ) ( ( length >> 16 ) & 0x00FF );
	bytes[3] = ( byte ) ( ( length >> 8 ) & 0x00FF );
	bytes[4] = ( byte ) ( length & 0x00FF );
	}

	return bytes;
	}
	}
	else
	{
	byte[] bytes = new byte[getNbBytes( length )];

	bytes[0] = ( byte ) 0x84;
	bytes[1] = ( byte ) ( length >> 24 );
	bytes[2] = ( byte ) ( ( length >> 16 ) & 0x00FF );
	bytes[3] = ( byte ) ( ( length >> 8 ) & 0x00FF );
	bytes[4] = ( byte ) ( length & 0x00FF );

	return bytes;
	}
	}


	/**
	* @return The parent.
	*/
	public TLV getParent()
	{
	return parent;
	}


	/**
	* @param parent The parent to set.
	*/
	public void setParent( TLV parent )
	{
	this.parent = parent;
	}


	/**
	* Get the TLV expected length.
	*
	* @return The expectedLength.
	*/
	public int getExpectedLength()
	{
	return expectedLength;
	}


	/**
	* Set the new expected length of the current TLV.
	*
	* @param expectedLength The expectedLength to set.
	*/
	public void setExpectedLength( int expectedLength )
	{
	this.expectedLength = expectedLength;
	}


	/**
	* @return The number of bytes necessary to store the TLV's length
	*/
	public int getLengthNbBytes()
	{
	return lengthNbBytes;
	}


	/**
	* Set the number of bytes we should use to store the TLV's length.
	*
	* @param lengthNbBytes The number of bytes necessary to store the TLV's length
	*/
	public void setLengthNbBytes( int lengthNbBytes )
	{
	this.lengthNbBytes = lengthNbBytes;
	}


	/**
	* @return the TLV's length
	*/
	public int getLength()
	{
	return length;
	}


	/**
	* Set the TLV's length
	*
	* @param length the TLV's length
	*/
	public void setLength( int length )
	{
	this.length = length;
	}


	/**
	* @return The currently read TLV's length bytes
	*/
	public int getLengthBytesRead()
	{
	return lengthBytesRead;
	}


	/**
	* Set the currently read TLV's length bytes.
	*
	* @param lengthBytesRead the currently read TLV's length bytes
	*/
	public void setLengthBytesRead( int lengthBytesRead )
	{
	this.lengthBytesRead = lengthBytesRead;
	}


	/**
	* Increment the number of bytes read for this TLV
	*
	*/
	public void incLengthBytesRead()
	{
	lengthBytesRead++;
	}


	/**
	* @return The TLV's ID
	*/
	public int getId()
	{
	return id;
	}


	/**
	* Get a String representation of the TLV
	*
	* @return A String
	*/
	@Override
	public String toString()
	{

	StringBuilder sb = new StringBuilder();

	sb.append( "TLV[ " );
	sb.append( Asn1StringUtils.dumpByte( tag ) ).append( ", " );
	sb.append( length ).append( ", " );
	sb.append( value.toString() );
	sb.append( "]" );

	return sb.toString();
	}
	}